Maximising the benefits of rainwater harvesting technology towards sustainability in urban areas of South Africa: a case study

ABSTRACT

Rainwater harvesting (RWH) technology has been in use for a long time, however its contribution towards urban water supply has been negligible in South Africa. Through a comprehensive literature review and analysis of interviews with key stakeholders, this case study presents implementation challenges and policy gaps in relation to the scale of adoption in the City of Johannesburg (CoJ). Findings show that only 0.1% of CoJ’s population utilises RWH due to various reasons, varying from financial viability, reliability, quality concerns, and system maintenance. This paper attributes these to the scale of adoption and suggests upscaling the system to larger commercial buildings to optimise benefits. However, there is an urgent need to bridge the policy gaps for successful implementation. Three categories of policy reforms are therefore proposed to facilitate innovation uptake, stakeholder engagement and compliance. This knowledge can guide future research towards urban water management, scientists and policymakers nexus.     

Urban water demand management: prospects and challenges for the developing countries

As the traditional supply-driven urban water management is not sustainable, water utilities should embrace water demand management (WDM) measures to meet increasing water demand. Developed countries are using different technological and management measures to reduce urban water demand as a part of their integrated urban water management strategy. However, all these measures might not be directly applicable for the developing countries. Furthermore, the developing countries might not have access to the technologies and skilled manpower as well as institutional set-up to apply these measures properly. In this context, this paper reviews the different tools, techniques and measures of urban water demand management (UWDM) applied in the developed countries and critically analyses the prerequisites, prospects and constraints likely to be faced in developing countries in adopting these techniques and measures. Furthermore, it outlines a set of activities that will best help the developing countries in attaining the full benefit of UWDM.     

Health and safety management in developing countries: a study of construction SMEs in Ghana

The construction industry plays a significant role in the economy of developing countries. The sector is, however, also one of the most hazardous with frequent accidents and health‐related problems. The health and safety practices of construction small and medium‐sized enterprises (SMEs) in Ghana are examined with a view to improving the health and safety performance of the sector. A survey questionnaire was administered to owner/managers of SMEs, with a response rate of 32% of the sampling frame. Few of the SMEs adopted proactive health and safety practices. However, health and safety practices identified as being particularly associated with firm characteristics were: accident investigation procedures; accident reporting procedures; use of health and safety posters; documentation of method statements; and health and safety inductions. The diversity of health and safety practices associated with different size categories of SMEs and constraints to improving health and safety are highlighted. A positive change is needed in the attitudes of owner/managers which takes into account size‐related constraints in order to improve the health and safety performance of Ghanaian SMEs.     

Sustainable water use and the nexus of behavioural intentions: the case of four South African communities

South Africa continues to ramp up public campaigns to rein in escalating water demand against the backdrop of dwindling and erratic supply. While the water conservation campaign appears to resonate with commercial and urban water users, it does not seem to have gained traction with rural and periurban residents. Using the sequential mixed methods, this paper explores the water conservation attitudes, behaviour and intentions of rural and periurban respondents in four South African communities. Results reveal respondents consider water conservation important and are favourably disposed to conserving water. Attitude, subjective norm and behavioural control emerged as significant factors influencing respondents’ water conservation intentions. The study concludes that rural and periurban residents are yet to develop a social ethic of water conservation essential in creating sustainability of resource use.     

某超高层建筑给水和热水系统设计

超高层建筑给水和热水系统应安全可靠、经济合理、高效节能。论文结合某工程实例,对给水和热水系统的设计进行了分析讨论,并介绍了采用的节水和节能措施。     

X市供水系统规划及问题探讨

对X市供水现状及存在的问题进行分析,介绍了X市供水系统规划的主要内容,并对规划中存在的水资源分析、供水设施设置、水源置换、节水潜能分析、污水回用、水价等问题进行了探讨。     

Managing water demand by contract: a survey of conservation outsourcing in China

The research was to gain insight into the characteristics, driving forces and barriers, specifications, and other issues of water conservation outsourcing contracts (OSCs) in China. Our analysis is based on information obtained from a pre-coded questionnaire, an assessment of OSC documents, and project on-site visits and interviews. The result shows that both parties of the OSCs lack knowledge and experience in preparing contracts. All eight contract documents are underspecified, which is the key reason for the existing disputes found in all OSCs studied. Recommendations are provided by this research to improve China's OSCs in the future.     

A sustainable framework for water resources management in an urban watershed: the case of Volos,Greece

The implementation of sustainable development principles in water resources management refers to an integrated management and coordination of the entirety of the actions and interventions that concern the water ecosystem, or parts of it, within a watershed. This procedure is accomplished through the development and application of an overall management plan at a hydrological basin level. This concept was followed by the water resources management plan of the city of Volos' watershed, which is presented in this paper. The main objective is the choice of the best set, among others, of hydraulic projects, which will be able to re-establish the balance in the basin's deficient water budget, satisfying at the same time future urban water demand. Decision making was carried out using a GIS tool and involved traditional water capture hydraulic projects on the one hand and sustainable water saving measures on the other. The whole procedure is being developed in an area with serious environmental problems, concerning mainly the groundwater resources. The particularity here is that the alternative solutions strongly depend on administrative agreement and consensus between relevant authorities.     

A review of residential water conservation tool performance and influences on implementation effectiveness

Water scarcity and household water consumption has received increasing attention on national public agendas in recent years. At the same time a number of important demand-side management (DSM) studies have been reported on by non-academic institutions, and there is a need for a comprehensive, up to date review of the impacts of DSM tools and the factors which influence their effectiveness. This paper aims to address an apparent lack of coverage in the academic literature by presenting a review of residential DSM tools using reports of recent DSM campaigns in the western (developed) world. The central objectives are to understand the potential for residential DSM tools to save water in different types of household under varying conditions and to identify influences on implementation effectiveness. In the discussion, we explore causes of uncertainty in DSM planning including the non-transferability of trends and existing methods of evaluation, and describe some of the resulting problems. The conclusions offer recommendations as to areas that require, and offer the greatest scope, for future research. This review article will be of interest to, among others, water company professionals, policy makers, regulators, researchers, and environmental agencies.     

河北省城市用水的健康循环与需求管理

分析了河北省城市用水、供水历年统计数据，结果表明，实施需水管理不仅可以减少水的社会循环规模，而且可以合理地预测未来城市用水需求，指导政府科学决策水工业设施政策；在河北省完全可取缔自备水井，这不仅有利于发挥公共供水企业规模效益，而且有利于实现水资源的持续开发利用。     

Water Supply and Demand Balances: Converting Uncertainty Into Headroom

This paper reports on research into the development of a standard procedure for calculating headroom. Headroom is a legitimate planning allowance to account for uncertainties in the supply/demand balance in a water-resource plan. Prior to this research, the UK water industry did not have an agreed method for calculating headroom, which resulted in inconsistencies in regulatory submissions. The research built on previous studies to define an approach that would be practical and easy to apply. A pragmatic methodology using a series of forms with clear guidelines was developed. The methodology has been applied in the 1998 supply/demand balance submissions to the regulatory authorities as part of the Asset Management Plan 3 periodic review.     

Water safety plans for piped urban supplies in developing countries: a case study from Kampala,Uganda

Full cost recovery is a major and complex issue that has gained high recognition in recent years. The Water Framework Directive promotes the idea that water charging should act as an incentive for the sustainable use of water resources. Thus, all Member States should take into consideration the principle of recovery of the total cost of water services, which includes environmental and resource costs as well. In order to evaluate various aspects of current water policy, to investigate the perspectives of water saving, to explore new approaches toward sustainable water management in the water supply sector and to evaluate water price elasticity, a survey has been performed recently in the city of Volos, concerning the residential sector. The influence of some selected variables is examined, residential water demand curve and water price elasticity are calculated. Estimations of future water demand under different pricing policies are also performed. Finally, the full water cost for the city of Volos is estimated and essential conclusions concerning water pricing and public participation are drawn.     

Public engagement with water conservation in London

Understanding water demand and consumers' capacity for change is essential in underpinning water demand management and water efficiency programmes. This paper presents the outcomes of a qualitative study, which used discussion groups relating to water infrastructure with environmentally aware citizens in five London boroughs in the Lower Lea River Basin. The results showed a subtle interaction between users, water and technology. Users are generally unaware of their own water consumption. Individual perceptions of changes in water behaviour are constrained by habit and lack of knowledge about what changes can be made and how. Knowledge of environmental information was described as the inspiration behind making any changes. The paper concludes that access to information about water resources, infrastructure and conservation measures should be enhanced because although information sources are abundant, participants claimed they were inaccessible without considerable effort. Finally, an emphasis should also be put on helping the public form a more substantial part in environmental decisions.     

Estimating Small Area Demand for Water: A New Methodology

The estimation of water demand is fundamental to effective water resource management. Water supply is measured at district level but true demand is not, and therefore studies of water-pricing relations are limited and mass-balance based assessment of leakage, illegal use, meter inaccuracies etc., are compromised. This paper describes the value and limitations of existing geodemographic methods, and an alternative technique widely used in other fields, microsimulation, is proposed. It is shown that geographic stability in demand relations is not found in all consumer commodities and cannot be assumed for water. Sampled data for Leeds, West Yorkshire, are used to construct a microsimulation model, and the results of that model are applied to the city of Leeds at ward level. Applicability is also demonstrated at enumeration district level.     

Cost-based analysis of quality in developing countries: a case study of building projects

This paper examines construction quality costs in Turkey. First, background information is presented on quality costing, on the prevention, appraisal, and failure (PAF) approach, and on PAF components. Secondly, a model is presented for determining the optimum level of total quality cost. Finally, a case study in which the costs of quality in a mass-housing project were collected and evaluated is presented. For the case study, the data were obtained in two stages: (i) during the construction period and (ii) after the delivery of residences. During the construction period, data were collected in collaboration with quantity surveyors and site engineers. During the delivery of residences, a questionnaire was administered to 655 householders, using face-to-face interviews. The importance of construction quality in a developing country was clarified by means of a cost-based analysis, in which the percentages of quality costs in the total cost to client were calculated separately, as was the optimum cost value of total quality.     

Water resources management in the Jordan River Basin

The Jordan River Basin is under great hydric stress. Increases in population and agricultural demand are contributing to the closure of the basin. This paper analyses the results of integrated water resources planning model (WEAP) by studying the vulnerability of water resources in the lower Jordan River under a changing climate pattern and growing water demands. Water balance models show that all aquifers supplying the city of Amman will be depleted within the next few decades. Mitigation measures should include the introduction of additional water into the basin through the Red Sea–Dead Sea canal, in addition to demand management measures such as water conservation and increase in irrigation efficiency. The findings of this study would provide a useful guide to the co‐riparians for policy formulation, decision making and dispute resolution. Cooperation among the five riparian countries may be improved by building a Geographic Information System (GIS) database that provides access to accurate data for hydrological analysis.     

Water demand management: implementation principles and indicative case studies

Current practices for the efficient use and management of water resources are based on the conjunctive application of water supply and demand measures. Even though options for the augmentation of water supply are widely analysed and assessed, water demand management remains an open field for study, as it is highly dependent on the socio‐economic features of a region and has a site‐specific character. This paper summarizes the guiding principles of demand management and presents some successful application examples of demand management measures from regions that cover a wide range of socioeconomic and environmental conditions in an effort to identify the critical factors for the efficient planning and implementation of demand management plans.     

高校校区给排水设计中的节能措施

针对高校校区工程特点,分别分析了生活给水系统、热水系统及排水系统中的节能措施在高校给排水设计中的可行性,并提出高校通过节水达到节能的几点措施,以达到最佳综合节能效果。     

高等学校照明节能改造——以四川某大学校区为例

我国校园照明用电节能潜力巨大.在大量浏览照明节能改造相关文献的基础上,通过市场调查和对成都3所高校的实地调研,以四川某大学主要教学楼为研究对象,对其进行高效照明节能改造方案设计,并对改造方案进行节能与经济分析,主要探究以LED照明替代教室现有照明的节能潜力与经济性,研究表明可将针对研究对象量化的节能潜力推广至全国高校.     

Chemical drinking water quality in Ghana: Water costs and scope for advanced treatment

To reduce child mortality and improve health in Ghana boreholes and wells are being installed across the country by the private sector, NGO's and the Ghanaian government. Water quality is not generally monitored once a water source has been improved. Water supplies were sampled across Ghana from mostly boreholes, wells and rivers as well as some piped water from the different regions and analysed for the chemical quality. Chemical water quality was found to exceed the WHO guidelines in 38% of samples, while pH varied from 3.7 to 8.9. Excess levels of nitrate (NO₃⁻) were found in 21% of the samples, manganese (Mn) and fluoride (F⁻) in 11% and 6.7%, respectively. Heavy metals such as lead (Pb), arsenic (As) and uranium (U) were localised to mining areas. Elements without health based guideline values such as aluminium (Al, 95%) and chloride (Cl, 5.7%) were found above the provisional guideline value.Economic information was gathered to identify water costs and ability to pay. Capital costs of wells and boreholes are about £1200 and £3800 respectively. The majority of installation costs are generally paid by the government or NGO's, while the maintenance is expected to be covered by the community. At least 58% of the communities had a water payment system in place, either an annual fee/one-off fee or “pay-as-you-fetch”. The annual fee was between £0.3-21, while the boreholes had a water collection fee of £0.07-0.7/m³, many wells were free. Interestingly, the most expensive water (£2.9-3.5/m³) was brought by truck. Many groundwater sources were not used due to poor chemical water quality. Considering the cost of unsuccessful borehole development, the potential for integrating suitable water treatment into the capital and maintenance costs of water sources is discussed. Additionally, many sources were not in use due to lack of water capacity, equipment malfunction or lack of economic resources to repair and maintain equipment. Those issues need to be addressed in combination with water quality, coordinated water supply provision and possible treatment to ensure sustainability of improved water resources.